Abstract
The nanofiltration of dairy ultrafiltration permeate can be used to produce a concentrated lactose product that is reduced in unwanted monovalent salts. In this paper, the surface charge of three nanofiltration membranes commonly used for such a purpose is examined. The focus is the impact of multivalent anions, notably phosphate and citrate, upon the surface charge of the membranes within a ternary system of potassium and calcium chloride. It was shown that these multivalent anions can influence the membrane charge through interactions with calcium, even though they are unlikely to adsorb to the membrane surface. Specifically, both phosphate and citrate can form soluble charged species with the calcium ions, reducing the net Ca 2+ concentration and hence the overall effect of calcium on the membrane. This ion interaction effect becomes more dominant at higher pH values, due to the greater tendency of calcium to interact with either phosphate or citrate at higher pH.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
